Phoenix-js-react-hooks - React Hooks for working with Phoenix Channels in JavaScript

@ericlathrop Just out of curiosity

export function useEventHandler(channel, event, handler) {
  const handlerFun = useRef(handler);
  handlerFun.current = handler;

Is there a reason for the 3rd line? Is this to dynamically change the handler? If so what are the use cases for this?